This Garmin Custom Map shows the Center City area of Philadelphia, Pennsylvania. Source: DVRPC 2005 Digital Orthoimagery from the Delaware Valley Regional Planning Commission. The .kmz file contains a total of 99 tiles @ 1024x1024 pixels (Garmin's format only supports a maximum of 100 tiles). Map resolution is 0.77 x 1.00 feet per pixel and the area covered is approximately 1.7 miles x 1.7 miles. File size is 20 MB. Garmin custom maps are only supported on the Oregon, Dakota and Colorado using current beta firmware as of this writing. Not compatible with Mapsource but the .kmz file can be opened in Google Earth as well as other programs. Cross-platform file, no installer needed. Simply drop the .kmz file into your CustomMaps folder on your gps.